In general, MOS devices have a very high input impedance which makes them sensitive to accumulation of static charges. This usually occurs from the mishandling of devices during processing, assembly or test. Such an accumulation of charges can cause a rupture of the gate dielectric which typically has a breakdown voltage of 50 to 100 volts. Such a rupture causes a short circuit between the surface metallization and the substrate material. To prevent such failures there is a need for effective protective devices at all MOS array inputs. There is a variety of such protection devices in use, such as Zener diodes, forward biased diodes, and MOS transistors. Descriptions of such devices and their operation can be found in many standard textbooks on MOS circuits, such as, for example, in "MOS Integrated Circuits" by the Engineering Staff of American Micro-Systems, Inc., published by Van Nostrand Reinhold Company in 1972. The addition of such devices at the MOS inputs tends to lower somewhat the normally high input resistance of the circuit and thus provide for current leakage that is undesirable for many applications that use MOS devices, especially for their high input resistance. Furthermore, such prior art protective devices have an additional disadvantage of being able to handle only a limited amount of current. An additional disadvantage of using such devices is that they can only handle pulses whose rise time is slower than their own turn-on speed.